Dobby mechanism



u Lampen H. STAUBLI DOBBY MECHANI SM Filed BUK, 28.. 1923 2 melk-Samt 1 Patented Nov. 11, 1924.

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HERMANIN' STUBLI, OF I-IOIRGEN, SWITZERLAND.

DOIBBY MECHANISIVI.

Application filed August 28, 1923.

To aZZ whom z'ft may concern:

Be it known that I, HERMANN STUBLI, a citizen of the Republic of Switzerland, residing at Horgen, in the Canton of Zurich, Republic of Switzerland, have invented certain new and useful Improvements in Dobby Mechanism, of which the following is a specification. k

This invention has for its object to provide an improved dobby mechanism. This improved mechanism has the advantages of a compact arrangement of its various mechanisms, steady running of the mechanism, and an excellent shedding. These results are attained by mounting the griff bars in levers to which rocking motion is imparted by means of cams mounted on a shaft arranged between the said levers and the ordinary rock-ing beams.

The accompanying drawings illustrate by wayof example a practical form of this invention applied to a double lift shedding machine, only such parts being shown as are necessary for the understanding of the invention.

In these drawings:-Figure 1 is a front elevation of the improved dobby mechanism. Figure la is a view drawn to a smaller scale of the adjacent parts of the right hand side of the loom in Figure 1.

Figure 2 is a plan of Figure l, and

Figure 3 is a partial side elevation.

As shown, a is the frame of the dobby mechanismi; b is a shaft mounted therein on which lare fiXed two cams c and cl. Each of these -cams has two eccentric portions 1-11 and III- IV (Fig. 1) and 'two concentric portions H-III andr I--IV between the outer ends of the eccentrie portions I-II and III-IV. l/Vhen the cams turn only the eecentric portons I-II and III-IV are operative while the concentric portions II-III and I-IV are inoperative. Shaft lb is driven by means of bevel wheels f, g

' from a shaft e driven continuously and positively by means of a. chain wheel k from a constantly rotating 'shaft (not shown) of the loom' 7L1. The griff bar levers i, k are supported in a rotary manner on the frame a by means of pins Z and m. Each of said levers carries an anti-friction roller n, 0 of which each bearsupon one of thecams c, cl. On

`each side of the mechanism there is provided a lever i and k. In each of the griff barrels p, g carried by the levers k, there is fixed one end of a rod t or u. These rods are Serial No. 659,819.

guided at their other ends each in an eye r ands of the frame a. These bars cause these grlff bars to maintain substantially their inclined position during the rocking movement of the levers and Zc.

The upper needle hooks o are arranged in the usual manner within the path of the griff bar p, whereas the lower needle hooks w are situated in the path of the griff bar q. Both groups of needles are actuated in a knownr manner by chains of cards (not shown). Each needle hooks o or w engages at its rear end a rocking beam m which, in the position shown in Figure V1, bears with its rear side against the two cross 'beamsl y and z. Each rocking beam engages at its centre with a rocker l which is in its turn pivotally mounted on a rod 2 of the machine frame a, and engages by means of a bar 3 a three-armed rocking lever 4 fixed on a shaft 5 mounted in the loom framing (Fig. la). The rocking lever 4 is connected by means of an arm 6 and rod 7 to an arm 8 of a rocking lever 9. The two rocking levers 11 and 9 .also carry by means of toothed Varms 10 and ll the cords 13 that carry the shafts or harness 12. The harness 12 is constantly being pvulled downwards by springe 111.

The parts/v, w, at, y, z, are well known to the men skilled in the art and form no parts of the invention, for that reason they are not represented especially in the F igs. 2 and 3.

The starting of the loom acts through the chain gear h, the shaft e and .the bevel gear f, g, to rotate also the operating shaft b with the cams c and (Z mounted thereon, with the result that the two griff bar levers i, are caused to rock in opposite directions.

In Figure 1 it is assumed that the cams o and CZ rotate in the direction of the arrow shown in this figure and that the upper needle hook o is in engagement with the griif bar g) of the lever lt, whilst the lower needle hook lw is out of engagement with the griif bar g of the lever i. During the time in which the eccentric portion I-TI of the cam (Z acts upon the lever Zz, the needle hook o is drawn to the left by the grifi' bar p carried by the lever k, so tha-t the upper part of the rocking beam is swung to the left, with the result that by means of the rocker 1 and the bar 3, the rocking levers land 9, the rod 7 and the cords 13, also the harness 12 is moved up into its highest position. During the time in which the concen- 1 ment with the grif bar g.

trio portion II-III of the cam d runs over the roller 0 of the lever 7c the latter is stationary and the harness remains in the highest position, so that the shuttle may pass through the open shed without touching the warp treads. During the time in which the eccentric portion III-IV of the cam d acts upon the lever k' (assuming that the hook 'w remains outside the path of the griif bar g), the heddles are depressed and the shed is closed chiefly by the action of the Springs 14. From the foregoing it will be easy to understand the operation in the case where the needle hook w is brought into engage- As will be perceived from Figure 1, the griff bars p and g are'carried by the levers i and k, and the latter are in their turn rocked directly by the cams c and d. Compared with known arrangements, the improved apparatus of the present invention has the advantage that no intermediate parts are required between the rocking levers and the Oriff bars, or between the former and the needle hooks fv, w, and that the shed is forcibly opened quickly and kept in open position by the cam c or cl until the shuttle has passed the shed and then the shed is closed.

The arrangement of the shaft b carryin the cams c and d between the levers i and on the one hand, and the rocking beams m on the other hand, in conjunction with the aforesaid absence of hitherto required intermediate parts, allows of giving a short overall length to the machine with the advantages of a considerable saving in weight and a substantial saving in superficial area, whereby the loom attendant is enabled to have a much better oversight of the entire loom.

The actuation of the griff bar levers i and la and consequently also of the heddles by cams, instead of by eccentrics as hitherto, effects a rapid and complete Opening and closing of the shed before and after the passage of the Shuttle, and enables the shed to remain stationary in its open position during the passage of the Shuttle, in addition to obviating the swmgmg or oscillatory movements in prior machines which cause a breaking ofr threads by the heddles which were to remain raised during a plurality of shuttle picks. By this means a good shedding and consequently steady running of the entire machine are assured.

As already stated, the` invention is illusi trated in this application to a double lift shaft machine, but it is applicable also to single lift shaft machines and to jacquard machines.

VVhat I claim is c 1. In a dobby mechanism the combination of two pairs of levers each of which is supported pivotally at one end on the machine framing, with two grif bars each of which is carried by the free ends of one of said pairs of levers, means for imparting opposite rocking movements to said pairs of levers, and means for maintaining said griff bars constantly in a determined position during and after said rocking moveme-nts.

2. ln a dobby mechanism the combination of two pairs of levers each lever of which is supported at one end pivotally on the machine framing, with two griff bars each of which is carried by the free ends ofone of said pairs of levers, a shaft, a cam for operating said two levers, fiXed on said shaft, for the purpose of imparting opposite rocking movements to said two levers, and means for maintaining said grifl' bars in a determined position during said rocking movements.

3. In a dobby mechanism, the combination of twopairs of levers each of which is supported at one end pivotally on the machine framing, with two`` griff bars each of which is carried by the free ends of one of said pairs of levers, a shaft, two cams fiXed on said shaft, each of which acts upon one of the said levers for the purpose of imparting opposite rocking movements thereto, and means for maintaining said griff bars in a predetermined position during and after said rocking movements.

4. In a dobby mechanism, the combination of two pairs of levers each lever of which is supported at one end pivotally on the machine framing, with two griff bars each of which is carried by the free ends of one of said pairs of levers, a continuously driven shaft, and two cams fixed on said shaft, each of which has two eccentric portions adapted to act upon one of the said levers and twoconcentric portions adapted to keep the rsaid lever stationary and the shed in open position between two rocking movements of the said lever, so that the Shuttle is absolutely free to pass through the shed.

5. In a dobby mechanism, the combination of two oriff bars, pairs of levers carrying said gritff bars, one of said pairs of levers having its fulcrum at the top, and the other of said pairs having its fulcrum at the bottom, two sets of needle hoo-ks arranged one above the other, each needle hook of which is adapted to be engaged with one of said griif bars, a fiXed rod, rocking beams located thereon, each of which is connected lat its other end to one of said needles, a

continuously driven shaft located between said levers and said rocking beams, and two cams fixed on said shaft each of which acts upon one of said levers whereby the latter are caused to;r make opposite rocking movements andremains steady between the rocking movements.

6. In a dobby mechanism, the combination of two pairs of levers of which one pair has an upper fulcrum and the other pair has a lower fulcrum, two griff bars each of which is carried by the free ends of one of said pairs of levers, a. rod for each griff bar, one end of which is attached to'its griff bar whilst its other end is guded slidably on the machine framing, so as to maintain said griff bars in a determined position durin their rocking` movements, two sets of nee le hooks located one above the other, of which each can be engaged at one end with one of said griff bars, a fixed rod, rocking beams located thereon, each of which is connected to the other end of one of said needles, a continuously driven shaft located between said levers and said rocking beams, and two cams fiXed on said shaft, each of which is adapted to act upon one of said levers whereby the latter are caused to make opposite rocking movements to cause a quick Opening of the shed and a steady opened shed during the time that the Shuttle passes therethrough.

In testimony Whereof I have affixed my signature.

HERMANN STUBLI. 

